The field of the invention is endoscopy.
Minimally invasive medical techniques are aimed at reducing the amount of extraneous tissue which must be damaged during diagnostic or surgical procedures, thereby reducing patient recovery time, discomfort, and deleterious side effects. Arthroscopic knee surgery is the most widely known example.
A shift to minimally-invasive medical surgery is expected to be one of the biggest trends in medical practice in the 1990's. There are tremendous incentives for the medical community to adopt these techniques. Approximately 21,000,000 surgeries are now performed each year in the United States. It is estimated that 8,000,000 of these surgeries can potentially be performed in a minimally invasive manner. However, only about 1,000,000 surgeries currently use these techniques, due in part to limitations in minimally invasive surgical technology.
Advances in minimally invasive surgical technology could have a dramatic impact. The average length of a hospital stay for a standard surgery is 8 days, while the average length for the equivalent minimally invasive surgery in 4 days. Thus, the complete adoption of minimally invasive techniques could save 28,000,000 hospital days, and billions of dollars annually in hospital residency costs alone. Patient recovery times, patient discomfort, surgical side effects, and time away from work are also reduced with minimally invasive surgery.
Most current minimally invasive medical surgery and diagnostic techniques can generally be classified into two categories: laparoscopy and endoscopy.
A laparoscope is used for minimally-invasive inspection and surgery inside the abdominal cavity. Currently, laparoscopes are generally simple unarticulated tools which are inserted into the abdominal cavity via a hole in the abdominal wall. The laparoscope tip is mounted with simple surgical tools, such as scissors, clamps, tissue samplers, or cauterizers.
An endoscope is a highly flexible device for non-invasive inspection in interior cavities, canals (such as the colon), vessels, etc. Current endoscopes are comprised mainly of a fiber optic bundle for transmitting an optical image, and perhaps some simple mechanism for steering the tip of the endoscope. Their fiber optic bundles can also transmit laser beams which can cut, cauterize, or vaporize tissue. The term laparoendoscopic refers to the collection of these minimally invasive surgical techniques.
Endoscopic diagnoses and surgery is performed by inserting an endoscope into a natural or surgically induced orifice, and primarily traversing the colon, arteries, or other interior ducts. Endoscopes are more often used for inspection of interior cavities, though laser surgery is increasingly prevalent. For example, endoscopic lasers have been used to pulverize and remove kidney stones. While there have been some dramatic successes with laparoscopic and endoscopic surgery, the current state of the art in laparoscopic and endoscopic design technology, and function remains quite primitive.
There are a number of disadvantages with current laparoendoscopic technology. Commercial endoscopes, while highly flexible, have only limited steering ability. They are difficult to position and cannot traverse tight bends in the intestine (or other interior ducts, such as arteries). Consequently, about 60% of the gastrointestinal track is unreachable with current endoscope technology. As a result, many diagnostic and surgical procedures in the gastrointestinal track require large abdominal incisions. Further, sudden changes in the internal anatomical structure, such as stomach or colon cramping, are not easily accommodated with current endoscopes.
One of the biggest impediments to the expansion of minimally invasive medical practice is lack of access to interior cavities. In all types of current minimally invasive approaches, the diagnostic and surgical tools are long, thin devices which are inserted into naturally or surgically produced orifices. However, current devices are extremely limited in their mobility and ability make tight bends and to negotiate complex interior structures.